This application claims the benefit of priority to Japanese Patent Application Nos. 2004-092219 filed on Mar. 26, 2004 and 2004-121623 filed on Apr. 16, 2004, both herein incorporated by reference.
1. Field of the Invention
The present invention relates to a printer which performs printing by mounting an ink cartridge containing ink or mounting a so-called pancake-shaped member having an ink ribbon therein, and more particularly to a printer which is designed to prevent an ink cartridge or a pancake-shaped member from being inappropriately reused.
2. Description of the Related Art
Conventional printers determine whether an appropriate ink cartridge is mounted therein by providing discriminating marks that indicate information about an ink ribbon contained in the ink cartridge, or information on colors and types of inks such as a liquid ink or toner, etc, reading the discriminating marks with sensors and by discriminating the information about the ink cartridge, in addition to determining the remaining amount of the ink in the ink cartridge and the appropriateness of the type of ink and printing paper to be used.
As an example of such a printer, a thermal transfer printer using an ink ribbon as ink will be described.
In a conventional thermal transfer printer 51, as shown in FIG. 7, a sheet guide plate 52b is formed in an inclined state on the right side (in the drawing) of a bottom plate 52a of a main case 52, in which a recording medium 53 is conveyed in the direction of an arrow A on the sheet guide plate 52b. 
Further, a cylindrical platen roller 54 is rotatably arranged on the left side (in the drawing) of the sheet guide plate 52b. 
Further, a thermal head 55 composed of a line head is arranged at an upper position facing the platen roller 54.
Here, the thermal head 55 is fastened to a head-mounting stage 56, and the head-mounting stage 56 is mounted to a head lever 57.
In the head lever 57, a round supporting hole 57a is formed at a position shown at the right side of the figure, and at a position shown at the other side the thermal head 55 is mounted to be rotatable about the supporting hole 57a. 
Further, a pair of the head levers 57 is arranged by facing each other to support both long ends of the thermal head 55.
In the main case 52, side plates 52c are arranged facing each other, a supporting shaft 58 pivoted to the side plates 52c is supported by the supporting hole 57a, thus making the head lever 57 is rotatable.
Further, the thermal head 55 engages and disengages the platen roller 54 by a vertical movement, that is, by rotating the head lever 57 up and down about the supporting hole 57a. 
A paper carrying roller 60 and a pressure contact roller 61 pressure-contacted therewith are arranged at a location further downstream than the platen roller 54 in the direction of the arrow A. Here, the pressure contact roller 61 is rotatably supported by a roller supporting case 62.
Further, an ink ribbon 63 is drawn between a thermal head 55 and the platen roller 54 while moving the thermal head in the upward direction. The ink ribbon 63 is received in a ribbon cartridge 64, its both ends are wound around a winding core 65 and a supplying core 66, and the ribbon cartridge 64 is detachably mounted to a cassette loading portion of the thermal transfer printer 51.
The winding core 65 and the supplying core 66 can be engaged with a winding bobbin 67 and a supplying bobbin 68 arranged in one of the side plates 52c of the main case 52.
Further, an ejection roller 69 for ejecting the recording medium 53 after printing is arranged at a location further downstream than the winding core 65 in the direction of the arrow A.
The print operation of the conventional thermal transfer printer 51 as mentioned above will be described. The head lever 57 is rotated up, the thermal head 55 is moved upward and the ribbon cartridge 64 is mounted on thermal printer.
Next, the recording medium 53 is carried in the direction of the arrow A and is supplied between the thermal head 55 in a head-up state and the platen roller 54.
Thereafter, the recording medium 53 which has passed between the thermal head 55 and the platen roller 54 is sandwiched between the paper carrying roller 60 and the pressure contact roller 61, and the thermal head 55 is headed down.
Then, a plurality of heater elements of the thermal head 55 is pressure-contacted with an outer peripheral face of the platen roller 54 with the recording medium 53 and the ink ribbon 63 interposed therebetween.
Next, the heater elements of the thermal head 55 are selectively heated on the basis of print information, and the paper carrying roller 60 is simultaneously rotated in a counterclockwise direction to convey the recording medium, thereby printing an image of desired colors on the recording medium 53.
After printing, the recording medium 53, in a state in which the paper carrying roller 60 and the pressure-contact roller 61 are detached from each other, is ejected to the outside as the paper ejection roller 69 is rotated in a counterclockwise direction.
Also, discriminating marks (not shown) having information, such as colors and types of ink ribbons, recorded thereon are provided on the side of the ink cartridge 64.
Each of the discriminating marks has a reference mark string, an identification mark string and a display space, which are formed on a sheet having a light-reflectable base.
The reference mark string is a set of reference marks indicating time-series references, that is, bit locations of information, and includes bar codes recorded and arrayed in dark portions which do not reflect light and are formed by recording.
Also, the identification mark string is a set of identification marks indicating the information about the ink ribbon and is composed of one-bit information on head location, four-bit information on colors and types of ink ribbons, a four-bit information on sheet number (four bits indicate 20 sheets, 50 sheets, 100 sheets, etc.), a ten-bit information on manufacturing company address, a two-bit information on reserve, which are arranged in order from the head correspondingly to locations of bits of the reference mark string. Moreover, in each bit of the identification mark string, the existence of a bit is recorded correspondingly on a dark portion which does not reflect light, and the non-existence of a bit is recorded correspondingly on the base. In addition, the width of one mark in the direction of the reference mark string is defined narrower than the width of a mark with a bit in the direction of the identification mark string.
Also, the display space is designed to display information on each ink ribbon as described above.
The discriminating marks are provided in such a manner that the array directions of the marks are parallel to the mounting direction of the ink cartridge 64 on the thermal transfer printer 51, that is, the rotation center of each bobbin. Meanwhile, two ink cartridge discriminating sensors (not shown) are attached to the thermal transfer printer 51 to read marks corresponding to the location of the reference mark string and the location of the identification mark string.
Moreover, a recording paper discriminating sensor (not shown) is attached to the thermal transfer printer 51 to read information on the manufacturing company and the quality of paper being used.
In the ink cartridge 64 and the thermal transfer printer 51 constructed this way, the ink cartridge 64 and recording paper are set prior to recording. At this time, information on the ink ribbons is input to a control unit of the thermal transfer printer 51 from each sensor, and information on the recording paper, that is, names of manufacturing companies, quality, etc. is input to the control unit from the paper discriminating sensor. The information obtained by these inputs is edited and displayed by a display unit (not shown) of the thermal transfer printer. If the name of the ink cartridge and the manufacturer of the recording paper do not match, the control unit outputs a warning display like “mismatching,” and protection is applied to stop the recording operation. When warning is not displayed, the control unit determines the recording sequence in accordance with the types of ribbon used and the recording operation is executed (for instance, refer to Japanese Unexamined Patent Application Publication No. 05-155123
Such a technique is not limited to the thermal transfer printers using ink cartridges, and is also applied to a thermal transfer printer using a pancake-shaped member that does not contain ink ribbons in the ink cartridge, an inkjet printer using an ink cartridge containing a liquid ink and to a paper printer using an ink cartridge containing toner.
However, in a printer using an ink cartridge having the above-described discriminating unit, only the ink cartridge is discriminated by reading the discriminating marks provided on the an ink cartridge with discriminating sensors. Therefore, when an ink cartridge which has been determined to be appropriate for the printer runs out of ink, users can often reuse the ink cartridge by supplying other ink to the depleted cartridge, or peels off the discriminating mark from the depleted cartridge and attach the mark to another ink cartridge, which is inappropriate. In this case, the printer incorrectly determines the new ink cartridge as being appropriate even though it is not. Because of this, if the new ink is not suitable for the printer, the quality of recording may deteriorate and, in severe cases, the printer may be damaged.